Youth Grindhouse Pro Pant. The Casual Racer. The Youth Grindhouse Pro Collection, designed with the racer in mind, features the Fasthouse athletic cut. With its sleek fit and superior materials, the Grindhouse Pro series will ensure you'll look great with increased performance. Athletic fit - tapered thighs and knees narrowing towards the ankle. Lightweight four-way stretch construction. Durable 450D reinforced panels and 600D saddle. Abrasion-resistant full-grain leather inner knee panels. Air-cooled stretch calf panel. Silky soft tricot 3/4-length knee brace optimized lining.